The invention relates to a preparation method of
calcitriol which is a compound material, belonging to the technical field of preparation of
drug synthesis and
organic compound synthesis. In the invention, the
calcifediol is taken as
raw material, a majority of produced impurities in the
chemical reaction process are removed through medium-pressure
liquid phase chromatography, wherein
calcifediol carried out sulfonylation and ring closing on
toluene, and the medium-pressure
liquid phase chromatography is used for removing the impurities; products carry out oxidation reaction, medium-pressure
chromatographic column separates and removes the impurities, ring opening is carried out, medium-pressure
liquid phase is added for coarsely separating stereoisomeride, and at last the products separated by high-pressure liquid phase
chromatography is hydrolyzed and refined to obtain the
calcitriol. The invention is reasonably selected, comprehensively applies the advantages of the medium and
high pressure liquid phase chromatography, has simple detaching method, can effectively remove the impurities, thoroughly separates the stereoisomeride, has high purity of the
calcitriol obtained from separation, has a productive rate of 40 percent, high yield and low cost, shortens production period, is suitable for
industrial scale, has application prospect, and provides a time-saving, economic and efficient method for the separation and the preparation of chiral compounds.